.clearfix:after {
  visibility: hidden;
  display: block;
  font-size: 0;
  content: " ";
  clear: both;
  height: 0;
}

h1 {
  margin: 0;
  padding: 10px; 
  background-color: #253440;
  color: #fff;
  border-bottom: 1px solid #263237;  
}

form {
  margin: 0;
  padding: 5px;
  background-color: #eee;
  border-bottom: 1px solid #999;  
}

input {  
  width: 70%;
  border: 1px solid #666;
  border-radius: 3px;
  padding: 5px;
  margin-right: 5px;
}

button {
  background-color: #2e75b3;
  color: #fff;
  border: 1px solid #666;
  border-radius: 3px;
  padding: 5px 10px;
}

#messages {
  list-style-type: none;
  margin: 0;
  padding: 0 15px;
}

#messages li {
  margin: 10px 0;
  padding: 0;
  border: 1px solid #ccc;
  border-radius: 5px;
}

.header {  
  font-size: 12px;
  color: #666;
  padding: 5px;
  background-color: #eee;
  border-bottom: 1px solid #ccc;
  border-top-left-radius: 5px;
  border-top-right-radius: 5px;
}

.me .header {
  background-color: lightyellow;
}

.who {
  float: left;
  font-weight: bold;  
}

.when {
  float: right;
  font-style: italic;
  color: #999;
}

.msg {
  padding: 5px;
}

.notice {
  padding: 5px;
  color: #999;
  font-style: italic;
}